Wheelchair seat back support



FIG. 1 is a perspective view of a wheelchair seat back support showing our new design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a back view thereof;

FIG. 6 is a left side view thereof, and,

FIG. 7 is a right side view thereof. 

CLAIM The ornamental design for a wheelchair seat back support, as shown and described. 